The subject matter disclosed herein relates generally to imaging systems and techniques, and more particularly to crystal arrays used in scintillators.
In certain types of imaging devices, such as positron emission tomography (PET) scanners, arrays of detector elements are used to detect radiation emanating from the patient. In a PET scanner, for example, arrays of scintillator crystals may be used to detect annihilation rays which are generated inside the patient. The annihilation rays are produced when a positron emitted from a radiopharmaceutical injected into the patient collides with an electron causing an annihilation event. The scintillator crystals receive the annihilation rays and generate light photons in response to the annihilation rays. The light photons are emitted from the scintillator crystals to a photosensor configured to convert the light energy from the light photons to electrical energy used to reconstruct an image.
Timing resolution of a time of flight (TOF) PET detector may depend on a number of components, including scintillation crystals and photosensors, and how the scintillation crystals and photosensors are combined into a detector along with readout electronics. Factors relating to the combination of the scintillation crystals and photosensors that may affect timing resolution include, for example, the light sharing scheme among the crystals and photosensors, the layout of photosensors, transit time spread between the photosensors, signal trace layout on amplifier board, and electronics noise.
Because of the high speeds of annihilation rays (e.g., the speed of light) and relatively short distances traveled by the annihilation rays during imaging, the timing resolution of detectors is important to imaging, especially considering the trending demands for higher image quality with improved timing resolution.